University of Ottawa

Displaying 1-40 of 74 results

  • White Papers // May 2014

    Cache-Enabled Small Cell Networks: Modeling and Tradeoffs

    The authors consider the problem of caching in next generation mobile cellular networks where Small Base Stations (SBSs) are able to store their users' content and serve them accordingly. The SBSs are stochastically distributed over the plane and serve their users either from the local cache or internet via limited...

    Provided By University of Ottawa

  • White Papers // Jul 2013

    Secure Hierarchical Virtual Private LAN Services for Provider Provisioned Networks

    Virtual Private LAN Service (VPLS) is a widely used Layer 2 (L2) Virtual Private Network (VPN) service. Initially, VPLS architectures were proposed as flat architectures. They were used only for small and medium scale networks due to the lack of scalability. Hierarchical VPLS architectures are proposed to overcome these scalability...

    Provided By University of Ottawa

  • White Papers // May 2013

    Technology Based-Entrepreneurship: Measurement Technology Perspective

    Currently, there are several papers on the New Technology Based Firms (NTBFs) yet the case studies of measurement technology appear to not be available. This paper aims to present the entrepreneurial processes of Finnish measurement technology firms. Eight interviews were conducted with the key players of the industry. Successfully, the...

    Provided By University of Ottawa

  • White Papers // Mar 2013

    Spatial Throughput of Wireless Networks Under Different Decoding Rules

    In this paper, the authors revisit the problem of characterizing the highest spatial throughput - or spatial capacity - of wireless networks in [bits/s/Hz/m2] in light of some recent results. They analyze the expected maximum achievable sum rates over a given area based on the capacity regions of Gaussian point-to-point...

    Provided By University of Ottawa

  • White Papers // Feb 2013

    Collaboration in Cloud Businesses - Value Networks and Ecosystems

    Cloud computing businesses are coined by broad and intense company collaboration. There is a growing need for clarification of the types of collaborative structures. In this paper, the authors draw on existing scientific discussions from the fields of value networks and business ecosystems and provide a typology of organisational collaboration...

    Provided By University of Ottawa

  • White Papers // Jan 2013

    Backhaul-Aware Self-Organizing Operator-Shared Small-Cell Networks

    Despite its notable importance, backhauling has - thus far - been a largely overlooked issue. However, driven by the uptake of small cell networks, current dedicated backhaul solutions are no longer viable for mobile operators, calling for novel deployment and backhaul-aware access strategies. In this paper, following the market's latest...

    Provided By University of Ottawa

  • White Papers // Nov 2012

    Decentralized Linear Transceiver Design in Coordinated Multi-Cell Multiuser MIMO Systems

    This paper considers a downlink linear transmit and receive beamformer design in a coordinated multi-cell network where each multiantenna Base Station (BS) serves its own set of multiple antenna users. Optimization objective is to minimize sum transmission power among coordinated BSs while satisfying user specific minimum SINR targets. The problem...

    Provided By University of Ottawa

  • White Papers // Oct 2012

    One Step Closer Towards e-Business - The Implementation of a Supporting ICT System

    This paper first reviews the thinking behind the Information and Communication Technology (ICT) utilization in supply chain integration as well as in e-supply design. This constructive research is conducted in a real life business network consisting of a number of Small and Medium-sized Enterprises (SMEs) operating in cooperation with one...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Rethinking Offload: How to Intelligently Combine Wi-Fi and Small Cells?

    As future Small Cell Base Stations (SCBSs) are set to be multi-mode capable (i.e., transmitting on both licensed and unlicensed bands), a cost-effective integration of both technologies/ systems coping with peak data demands, is crucial. Using tools from Reinforcement Learning (RL), a distributed cross-system traffic steering framework is proposed, whereby...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Two-Level Decomposition Method for Resource Allocation in Telecommunication Networks

    In this paper, the authors consider a two-level problem of resource allocation in a telecommunication network divided into zones. At the upper level the network manager distributes homogeneous resource shares among zones in order to maximize the total network profit, which takes into account the inner zonal payments from users...

    Provided By University of Ottawa

  • White Papers // May 2012

    Coordinated Downlink Precoder Design for Regenerative Multi-User Relaying

    Regenerative relaying is an efficient method of increasing the achievable capacity and cell coverage. The authors propose a weighted mean squared error (WMSE) minimization based throughput maximizing precoder design subject to separate sum transmit power constraints for the base station (BS) and relay station (RS). The proposed algorithm is implemented...

    Provided By University of Ottawa

  • White Papers // May 2012

    Constellation Design and Mapping for Partially Coherent Correlated Channel With Coding

    Space-Time (ST) constellation design problem and bit mapping schemes for Multiple-Input Multiple-Output (MIMO) systems in correlated Rayleigh fading channels with imperfect channel estimation at the receiver are considered. The channel coefficients are assumed to be correlated in space and uncorrelated in time from one coherence interval to another after which...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Per-Antenna Power Constraint: Optimal and Suboptimal Designs

    This paper considers the pre-coder designs for Successive Zero-Forcing Dirty Paper Coding (SZF-DPC), a suboptimal transmission technique for MIMO Broadcast Channels (MIMO BCs). Existing pre-coder designs for SZF-DPC often consider a sum power constraint. In this paper, the authors address the pre-coder design for SZF-DPC with Per-Antenna Power Constraints (PAPCs),...

    Provided By University of Ottawa

  • White Papers // May 2012

    Learning Coarse Correlated Equilibria in Two-Tier Wireless Networks

    In this paper, the authors study the strategic coexistence between macro and femto cell tiers from a game theoretic learning perspective. A novel regret-based learning algorithm is proposed whereby cognitive femtocells mitigate their interference toward the macrocell tier, on the downlink. The proposed algorithm is fully decentralized relying only on...

    Provided By University of Ottawa

  • White Papers // May 2012

    Error Resistant Lossless Data Compression With Equal Length Coding Using Fine Tuned Multiple Label Mapping

    Data inherently including memory can be compressed using either equal or variable length coding. This paper proposes a novel method to compress the data with memory by using equal length code words while maintaining the error correction capability. The main drawback of Variable Length Coding (VLC) is that because of...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Sum Power Constraint: Low-Complexity Optimal Designs

    Successive Zero-Forcing Dirty Paper Coding (SZFDPC) is a simplified alternative to DPC for MIMO Broadcast Channels (MIMO BCs). In the SZF-DPC scheme, the non-causally known interference is canceled by DPC, while the residual interference is suppressed by the ZF technique. Due to the ZF constraints, the precoders are constrained to...

    Provided By University of Ottawa

  • White Papers // May 2012

    Expressivity of Time-Varying Graphs and the Power of Waiting in Dynamic Networks

    In infrastructure-less highly dynamic networks, computing and performing even basic tasks (such as routing and broadcasting) is a very challenging activity due to the fact that connectivity does not necessarily hold, and the network may actually be disconnected at every time instant. Clearly the task of designing protocols for these...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Implementation of LS, MMSE and SAGE Channel Estimators for Mobile MIMO-OFDM

    The use of Decision Directed (DD) channel estimation in a Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) downlink receiver is explained in this paper. The 3GPP Long Term Evolution (LTE) based pilot structure is used as a benchmark. The Space-Alternating Generalized Expectation-maximization (SAGE) algorithm is used to improve the...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Building Fastest Broadcast Trees in Periodically-Varying Graphs

    Delay-Tolerant Networks (DTNs) are characterized by a possible absence of end-to-end communication routes at any instant. Still, connectivity can generally be established over time and space. The optimality of a temporal path (journey) in this context can be defined in several terms, including topological (e.g. shortest in hops) and temporal...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Transformation Toward a Cloud Business Model

    Cloud technologies have widely been discussed within telecommunications research and practice. Compared to traditional software product business, the cloud enabled service business can be significantly different in nature. Therefore the transformation resulting in the implementation of cloud technologies can be drastic. There are gaps in current literature in the business...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Performance of Transmit Antenna Selection Physical Layer Security Schemes

    The authors analyze the PHYsical layer (PHY) security of a communication scheme consisting of a multiple antenna transmitter with a single Radio Frequency (RF) chain using Transmitter Antenna Selection (TAS) and a single antenna receiver, in the presence of a sophisticated multiple antenna eavesdropper. They develop closed-form expressions for the...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Cooperative Redundancy Elimination in Data Center Networks With Wireless Cards at Routers

    The authors consider architecture of Data Center Networks (DCN), which adds wireless network card to each router. Existing Redundancy Elimination (RE) mechanisms reduce link loads and increase network capacity in several environments by removing strings that have appeared in earlier packets through encoding and decode them several hops downstream. This...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Energy Efficient MIMO Two-Way Relay System With Physical Layer Network Coding

    The authors investigate error performance and an optimum power allocation scheme for Multiple-Input Multiple-Output (MIMO) channel Physical layer Network Coding (PNC) based two-way relay system. Zero forcing pre-coding technique is used at source nodes to facilitate PNC operations at the relay node. First, system error performance is investigated by introducing...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    New Double Layer Space-Time Block Code for Distributed 4 X 2 MIMO Systems

    Multiple-Input Multiple-Output (MIMO) techniques have become important part of broadband wireless communication system. Several MIMO Space-Time Block Coding (STBC) techniques have been proposed and widely studied during the last 10 - 15 years and different solutions have been adopted in various wireless standards. The optimal STBC design criteria were proposed...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Hypothesis Testing and Decision Theoretic Approach for Fault Detection in Wireless Sensor Networks

    Sensor networks aim at monitoring their surroundings for event detection and object tracking. But due to failure or death of sensors, false signal can be transmitted. In this paper, the authors consider the problem of fault detection in Wireless Sensor Network (WSN), in particular, addressing both the noise-related measurement error...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Adaptively Secure Broadcast Encryption With Short Ciphertexts

    The authors propose an adaptively secure broadcast encryption scheme with short ciphertexts, where the size of broadcast encryption message is fixed regardless of the size of the broadcast group. In their proposed scheme, members can join and leave the group without requiring any change to public parameters of the system...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    Time-Varying Graphs and Dynamic Networks

    The past few years have seen intensive research efforts carried out in some apparently unrelated areas of dynamic systems - delay-tolerant networks, opportunistic-mobility networks, social networks - obtaining closely related insights. Indeed, the concepts discovered in these investigations can be viewed as parts of the same conceptual universe; and the...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    On the Feasibility of Maintenance Algorithms in Dynamic Graphs

    Near ubiquitous mobile computing has led to intense interest in dynamic graph theory. This provides a new and challenging setting for algorithmic and complexity theory. For any graph-based problem, the rapid evolution of a (possibly disconnected) graph over time naturally leads to the important complexity question: is it better to...

    Provided By University of Ottawa

  • White Papers // Jan 2012

    Distributed Computing in Dynamic Networks: Towards a Framework for Automated Analysis of Algorithms

    Besides the complexity in time or in number of messages, a common approach for analyzing distributed algorithms is to look at the assumptions they make on the underlying network. The authors investigate this question from the perspective of network dynamics. In particular, they ask how a given property on the...

    Provided By University of Ottawa

  • White Papers // Jan 2012

    Successful Performance Measurement in SMEs Through Personnel Participation

    Balanced scorecard has proven to be a functional tool for large companies; however, Small- and Medium-sized Enterprises (SME) have experienced it too complicated for their purposes. The aim of this research is to analyze the potential of simplifying balanced scorecard in order to acknowledge the practical realities of SMEs. The...

    Provided By University of Ottawa

  • White Papers // Nov 2011

    Autoregressive Trust Management in Wireless Ad Hoc Networks

    In this paper, the authors propose a novel trust management scheme for improving routing reliability in wireless ad hoc networks. It is grounded on two classic auto-regression models, namely Auto-Regressive (AR) model and Auto-Regressive with eXogenous inputs (ARX) model. According to this scheme, a node periodically measures the packet forwarding...

    Provided By University of Ottawa

  • White Papers // Oct 2011

    LaConf: A Localized Address Autoconfiguration Scheme for Wireless Ad Hoc Networks

    The authors propose a Localized Address auto-Configuration (LaConf) scheme for wireless ad hoc networks. Address allocation information is maintained on the network border nodes, called Addressing Agents (AAs), which are locally identified by a geographic routing protocol GFG (Greedy-FACE-Greedy). When a node joins the network, it acquires an address from...

    Provided By University of Ottawa

  • White Papers // Sep 2011

    Learning Coarse Correlated Equilibrium in Two-Tier Wireless Networks

    In this paper, the authors study the strategic coexistence between macro and femtocell tiers, from a game theoretic perspective. A novel regret based learning algorithm is proposed whereby cognitive femtocells mitigate their interference toward the macrocell, on the downlink. The proposed algorithm is fully decentralized relying only on the Signal-to-Interference-plus...

    Provided By University of Ottawa

  • White Papers // Aug 2011

    On the Temporal Analysis of Scientific Network Evolution

    In this paper, the authors approach the definition of new methodologies for the visualization and the exploration of social networks and their dynamics. They present a recently introduced formalism called TVG (for Time-Varying Graphs), which was initially developed to model and analyze highly-dynamic and infrastructure-less communication networks, and TVG derived...

    Provided By University of Ottawa

  • White Papers // Jun 2011

    Using Diffusive Load Balancing to Improve Performance of Peer-to-Peer Systems for Hosting Services

    This paper presents a diffusive load balancing algorithm for peer-to-peer systems. The algorithm reduces the differences of the available capacities of the nodes in the system using service migrations between nodes in order to obtain similar performance for all nodes. The authors propose algorithms for handling homogeneous services, i.e., services...

    Provided By University of Ottawa

  • White Papers // May 2011

    Measuring Temporal Lags in Delay-Tolerant Networks

    Delay-Tolerant Networks (DTNs) are characterized by a possible absence of end-to-end communication routes at any instant. In most cases, however, a form of connectivity can be established over time and space. This particularity leads to consider the relevance of a given route not only in terms of hops (topological length),...

    Provided By University of Ottawa

  • White Papers // Mar 2011

    Data-Centric Misbehavior Detection in VANETs

    Detecting misbehavior (such as transmissions of false information) in Vehicular Ad hoc NETworks (VANETs) is very important problem with wide range of implications including safety related and congestion avoidance applications. The authors discuss several limitations of existing Misbehavior Detection Schemes (MDS) designed for VANETs. Most MDS are concerned with detection...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    Fully Secure Pairwise and Triple Key Distribution in Wireless Sensor Networks Using Combinatorial Designs

    Sensor nodes are small battery powered devices which are deployed in large numbers to sense and collect information for various applications ranging from health care to military. Sensor networks need to rely on some cryptographic mechanism to communicate securely. Due to the resource constrained nature of sensor nodes, the symmetric...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    A Dominating Sets and Target Radius Based Localized Activity Scheduling and Minimum Energy Broadcast Protocol for Ad Hoc and Sensor Networks

    Several localized broadcasting protocols for ad hoc and sensor networks were proposed recently, with the goal of minimizing the energy consumption, while still guaranteeing a total coverage of the network. Also, several activity scheduling protocols were proposed, which select nodes in a connected dominating set to be active, with the...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    Localized Energy Efficient Broadcast for Wireless Networks With Directional Antennas

    Directional antennas reduce the beamwidth angle to diffuse the radio transmission to one direction and thus useless energy than omnidirectional antennas. Combined with the idea of reducing the transmission power, these devices can be used for the minimal energy broadcasting problem. The problem is to minimize the total energy consumption...

    Provided By University of Ottawa

  • White Papers // Jun 2009

    Using Geometrical Routing for Overlay Networking in MMOGs

    Massively Multiplayer Online Games (MMOG) is one of the brightest assets in the world of e-Entertainment. The primary interest of MMOG applications is to transfer huge amounts of update messages to a particular geographic region in a virtual space. It deals with colossal number of online players who are constantly...

    Provided By University of Ottawa

  • White Papers // Jan 2010

    Specification and Validation of Telephone Systems in LOTOS

    LOTOS (Language of Temporal Ordering Specification) is a Formal Description Technique that was developed by the ISO for the specification of OSI services and protocols. This paper presents a design methodology for the description in LOTOS of telephone systems with modern telephone features. The description of a Sample Telephone System...

    Provided By University of Ottawa

  • White Papers // Jun 2009

    A Distributed Camera Network Architecture Supporting Video Adaptation

    Sparked by the desire to secure human presence in high risk areas, this paper proposes a distributed camera network architecture. This architecture is intended as a robust platform for video surveillance systems. In addition, the proposed system has the ability to collect/capture video streams from cameras at a point-of-interest and...

    Provided By University of Ottawa

  • White Papers // Jan 2010

    GPS Based Distributed Routing Algorithms for Wireless Networks

    Recently, several fully distributed (localized) GPS based routing protocols for a Mobile Ad hoc NETwork (MANET) were reported in literature. They are variations of directional (DIR) routing methods, in which node A (the source or intermediate node) transmits a message m to several neighbors whose direction is closest to the...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    On The Determinants Of The Reach Of Innovation-Related Collaboration In Small Firms

    This paper takes as its starting point an item of relatively recent academic orthodoxy: the insistence that 'Interactive learning and collective entrepreneurship are fundamental to the process of innovation' (Lundvall, 1992, p. 9). From this, academics have frequently taken "Interactive" to imply "Inter-organisational" and, whilst one might be concerned by...

    Provided By University of Ottawa

  • White Papers // Mar 2011

    Data-Centric Misbehavior Detection in VANETs

    Detecting misbehavior (such as transmissions of false information) in Vehicular Ad hoc NETworks (VANETs) is very important problem with wide range of implications including safety related and congestion avoidance applications. The authors discuss several limitations of existing Misbehavior Detection Schemes (MDS) designed for VANETs. Most MDS are concerned with detection...

    Provided By University of Ottawa

  • White Papers // Mar 2009

    GeoP2P: An Adaptive Peer-to-Peer Overlay for Efficient Search and Update of Spatial Information

    This paper proposes a fully decentralized peer-to-peer overlay structure GeoP2P, to facilitate geographic location based search and retrieval of information. Certain limitations of centralized geographic indexes favor peer-to-peer organization of the information, which, in addition to avoiding performance bottleneck, allows autonomy over local information. Peer-to-peer systems for geographic or multidimensional...

    Provided By University of Ottawa

  • White Papers // Mar 2009

    Decentralized Management of Bi-Modal Network Resources in a Distributed Stream Processing Platform

    This paper presents resource management techniques for allocating communication and computational resources in a distributed stream processing platform. The platform is designed to exploit the synergy of two classes of network connections dedicated and opportunistic. Previous studies the authors conducted have demonstrated the benefits of such bi-modal resource organization that...

    Provided By University of Ottawa

  • White Papers // Mar 2009

    Overlay Structure for Large Scale Content Sharing: Leveraging Geography as the Basis for Routing Locality

    In this paper the authors place the arguments on two related issues in the design of generalized structured peer-to-peer overlays. First, they argue that for the large-scale content-sharing applications, lookup and content transport functions need to be treated separately. Second, to create a location-based routing overlay suitable for content sharing...

    Provided By University of Ottawa

  • White Papers // Apr 2009

    Distributed Maintenance of Anytime Available Spanning Trees in Dynamic Networks

    This paper investigates the problem of building and maintaining distributed spanning trees in dynamic networks. Contrarily to previous solutions, the authors do not assume the existence of stabilization periods between topological changes, and address the more general case where such changes may occur at anytime and disconnect the network. Hence,...

    Provided By University of Ottawa

  • White Papers // Jul 2010

    Magnetic-Field Coupling Characteristics of Ferrite-Coil Antennas for Low-Frequency RFID Applications

    Low-frequency technology has been widely used for detecting objects placed underground. Low-frequency Radio-Frequency IDentification (RFID) systems provide the advantage of better propagation in lossy materials such as rocks and soil. In this paper, the authors assume that buried objects will be tagged with low frequency RFID passive transponders and that...

    Provided By University of Ottawa

  • White Papers // May 2010

    Efficient Algorithm for Redundant Reader Elimination in Wireless RFID Networks

    Radio Frequency IDentification (RFID) systems, due to recent technological advances, are being deployed in large scale for different applications. However, this requires a dense deployment of readers to cover the working area. Without optimizing reader's distribution and number, many of the readers will be redundant, reducing the efficiency of the...

    Provided By University of Ottawa

  • White Papers // Dec 2009

    Complexity Analysis of Featured-Based Image Matching

    fundamental problem in computer vision is to map a pixel in one image to a pixel in another image of the same scene. This is called the image correspondence problem. Many algorithms have been proposed in literature to solve the problem, however no rigorous analysis has been conducted to study...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    A Dominating Sets and Target Radius Based Localized Activity Scheduling and Minimum Energy Broadcast Protocol for Ad Hoc and Sensor Networks

    Several localized broadcasting protocols for ad hoc and sensor networks were proposed recently, with the goal of minimizing the energy consumption, while still guaranteeing a total coverage of the network. Also, several activity scheduling protocols were proposed, which select nodes in a connected dominating set to be active, with the...

    Provided By University of Ottawa

  • White Papers // Nov 2010

    A Real-Time Browser-Based Collaboration System for Synchronized Online Multimedia Sharing

    The amount of multimedia content on the web has been growing at a staggering rate, and users are increasingly looking to share it with colleagues and friends in real-time. Several commercial, open source and academic solutions have attempted to make it easier to share a large variety of online content...

    Provided By University of Ottawa

  • White Papers // Nov 2010

    Towards A Cloud Optimization Architecture Using Strategy-Trees

    Cloud computing represents an emerging approach to on-demand computing. This paper proposes an extension to a three-layered cloud computing architecture through the use of strategy-trees. Managers at each layer of the cloud architecture, representing a provider's perspective, will utilize strategy-trees to implement feedback loops to achieve sets of objectives over...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    Localized Energy Efficient Broadcast for Wireless Networks With Directional Antennas

    Directional antennas reduce the beamwidth angle to diffuse the radio transmission to one direction and thus useless energy than omnidirectional antennas. Combined with the idea of reducing the transmission power, these devices can be used for the minimal energy broadcasting problem. The problem is to minimize the total energy consumption...

    Provided By University of Ottawa

  • White Papers // May 2010

    The One-Commodity Traveling Salesman Problem With Selective Pickup and Delivery: An Ant Colony Approach

    The authors introduce a novel combinatorial optimization problem: the One-commodity Traveling Salesman Problem with SELective Pickup and Delivery (1-TSP-SELPD), characterized by the fact that the demand of any delivery customer can be met by a relatively large number of pickup customers. While all delivery spots are to be visited, only...

    Provided By University of Ottawa

  • White Papers // Feb 2009

    Localized Sensor Self-Deployment for Guaranteed Coverage Radius Maximization

    Focused coverage is defined as the coverage of a wireless sensor network surrounding a Point Of Interest (POI), and is measured by coverage radius, i.e., minimum distance from POI to uncovered areas. Sensor self-deployment algorithm GRG is designed for autonomous focused coverage formation. It however does not always produce optimal...

    Provided By University of Ottawa

  • White Papers // Jan 2009

    Exploiting Actuator Mobility for Energy-Efficient Data Collection in Delay-Tolerant Wireless Sensor Networks

    A Wireless Sensor Network (WSN) is a large-scale ad hoc multi-hop network deployed (usually, at random) in a region of interest for surveillance purpose. One of its fundamental tasks is to gather sensor readings from the sensory field at data sinks. Research has shown that sensors near a sink deplete...

    Provided By University of Ottawa

  • White Papers // Dec 2009

    Multiratecast in Wireless Fault Tolerant Sensor and Actuator Networks

    The authors study the multicast problem in wireless sensor networks, where the source can send data to a fixed number of destinations (actuators) at a different rate (multiratecast). A typical motivation of such communication scheme is to enable fault tolerant monitoring applications where data is reported to more than one...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    Topology Control in Sensor, Actuator and Mobile Robot Networks

    The efficiency of many sensor network algorithms depends on characteristics of the underlying connectivity, such as the length and density of links. It is therefore a common practice to control the number and nature of links that are to be used among all potentially available links. Such topology control can...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    Multicasting, Geocasting, and Anycasting in Sensor and Actuator Networks

    This paper reviews the scenarios where a given message is sent from a single source to possibly several destinations. These scenarios can be subdivided into multicasting, geocasting, multiratecasting, and anycasting. In multicasting, a given message must be routed from one node to a number of destinations whose locations may be...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    Fully Secure Pairwise and Triple Key Distribution in Wireless Sensor Networks Using Combinatorial Designs

    Sensor nodes are small battery powered devices which are deployed in large numbers to sense and collect information for various applications ranging from health care to military. Sensor networks need to rely on some cryptographic mechanism to communicate securely. Due to the resource constrained nature of sensor nodes, the symmetric...

    Provided By University of Ottawa

  • White Papers // Jun 2011

    Using Diffusive Load Balancing to Improve Performance of Peer-to-Peer Systems for Hosting Services

    This paper presents a diffusive load balancing algorithm for peer-to-peer systems. The algorithm reduces the differences of the available capacities of the nodes in the system using service migrations between nodes in order to obtain similar performance for all nodes. The authors propose algorithms for handling homogeneous services, i.e., services...

    Provided By University of Ottawa

  • White Papers // Feb 2009

    Applying a Diffusive Load Balancing in a Clustered P2P System

    Although a large number of users are using P2P systems, the ability of these systems to provide services with quality is questioned. A load balanced P2P system can provide services with smaller failure rate and better performance; hence, service quality of the system can be improved. Cluster systems have been...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    Some Modeling Challenges When Testing Rich Internet Applications for Security

    Web-based applications are becoming more ubiquitous day by day, and among these applications, a new trend is emerging: Rich Internet Applications (RIAs), using technologies such as Ajax, Flex, or Silverlight, break away from the traditional approach of Web applications having server-side computation and synchronous communications between the web client and...

    Provided By University of Ottawa

  • White Papers // Sep 2009

    A Diffusive Load Balancing Scheme for Clustered Peer-to-Peer Systems

    Node clustering is an effective solution for achieving good performance and high reliability for Peer-To-Peer (P2P) systems. To improve the performance of a clustered P2P system, it is important to balance the service load among the clusters in the system. In this paper, the authors describe a diffusive load balancing...

    Provided By University of Ottawa

  • White Papers // Jul 2009

    Peer-to-Peer Platforms for High-Quality Web Services: The Case for Load-Balanced Clustered Peer-to-Peer Systems

    This paper presents a clustered peer-to-peer system as a resource organization structure for web-service hosting platforms where service quality such as response time and service availability are provided with assurance. The peer-to-peer organization allows integration of autonomous resources into a single platform in a scalable manner. In clustered peer-to-peer systems,...

    Provided By University of Ottawa

  • White Papers // Oct 2009

    A Locality Preserving Routing Overlay Using Geographic Coordinates

    This paper presents a design for a general locality preserving routing overlay network based on geographic coordinates of nodes. For efficient use of network resources, it is important to follow some locality principles while routing bulk multimedia content. The proposed overlay network creates the interconnection among large number of highly...

    Provided By University of Ottawa

  • White Papers // Nov 2008

    CliqueStream: Creating an Efficient and Resilient Transport Overlay for Peer-to-Peer Live Streaming Using a Clustered DHT

    With the widespread adoption of broadband residential Internet access, live multimedia streaming over the IP network may be envisioned as a dominating application on the next generation Internet. Global presence of the IP network makes it possible to deliver large number of commercial as well as amateur TV channels to...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Adaptively Secure Broadcast Encryption With Short Ciphertexts

    The authors propose an adaptively secure broadcast encryption scheme with short ciphertexts, where the size of broadcast encryption message is fixed regardless of the size of the broadcast group. In their proposed scheme, members can join and leave the group without requiring any change to public parameters of the system...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Hypothesis Testing and Decision Theoretic Approach for Fault Detection in Wireless Sensor Networks

    Sensor networks aim at monitoring their surroundings for event detection and object tracking. But due to failure or death of sensors, false signal can be transmitted. In this paper, the authors consider the problem of fault detection in Wireless Sensor Network (WSN), in particular, addressing both the noise-related measurement error...

    Provided By University of Ottawa

  • White Papers // Apr 2010

    Reasoning With Higher-Order Abstract Syntax and Contexts: A Comparison

    A variety of logical frameworks support the use of Higher-Order Abstract Syntax (HOAS) in representing formal systems given via axioms and inference rules and reasoning about them. In such frameworks, object-level binding is encoded directly using meta-level binding. Although these systems seem superficially the same, they differ in a variety...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Cooperative Redundancy Elimination in Data Center Networks With Wireless Cards at Routers

    The authors consider architecture of Data Center Networks (DCN), which adds wireless network card to each router. Existing Redundancy Elimination (RE) mechanisms reduce link loads and increase network capacity in several environments by removing strings that have appeared in earlier packets through encoding and decode them several hops downstream. This...

    Provided By University of Ottawa

  • White Papers // May 2012

    Coordinated Downlink Precoder Design for Regenerative Multi-User Relaying

    Regenerative relaying is an efficient method of increasing the achievable capacity and cell coverage. The authors propose a weighted mean squared error (WMSE) minimization based throughput maximizing precoder design subject to separate sum transmit power constraints for the base station (BS) and relay station (RS). The proposed algorithm is implemented...

    Provided By University of Ottawa

  • White Papers // May 2012

    Constellation Design and Mapping for Partially Coherent Correlated Channel With Coding

    Space-Time (ST) constellation design problem and bit mapping schemes for Multiple-Input Multiple-Output (MIMO) systems in correlated Rayleigh fading channels with imperfect channel estimation at the receiver are considered. The channel coefficients are assumed to be correlated in space and uncorrelated in time from one coherence interval to another after which...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Per-Antenna Power Constraint: Optimal and Suboptimal Designs

    This paper considers the pre-coder designs for Successive Zero-Forcing Dirty Paper Coding (SZF-DPC), a suboptimal transmission technique for MIMO Broadcast Channels (MIMO BCs). Existing pre-coder designs for SZF-DPC often consider a sum power constraint. In this paper, the authors address the pre-coder design for SZF-DPC with Per-Antenna Power Constraints (PAPCs),...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Energy Efficient MIMO Two-Way Relay System With Physical Layer Network Coding

    The authors investigate error performance and an optimum power allocation scheme for Multiple-Input Multiple-Output (MIMO) channel Physical layer Network Coding (PNC) based two-way relay system. Zero forcing pre-coding technique is used at source nodes to facilitate PNC operations at the relay node. First, system error performance is investigated by introducing...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    New Double Layer Space-Time Block Code for Distributed 4 X 2 MIMO Systems

    Multiple-Input Multiple-Output (MIMO) techniques have become important part of broadband wireless communication system. Several MIMO Space-Time Block Coding (STBC) techniques have been proposed and widely studied during the last 10 - 15 years and different solutions have been adopted in various wireless standards. The optimal STBC design criteria were proposed...

    Provided By University of Ottawa